[Ruthless Invader] Raditz is a solid Free-To-Play unit with an AoE Super Attack; he can be used to beat the World Tournament in the lower levels of difficulty.
This is by no means a competitive team, its main purpose so far is to farm the [Stubborn Low-Class Warrior] Story Event. On this team Raditz does not struggle for Ki, the 4 Ki from each Leader Skill combined with his self-sufficiency brings him well over what he needs to Super Attack; he should be paired with either Atrocious Crackdown Raditz (Giant Ape) or Low-Class, High-Octane Bardock (Giant Ape) on the other one.
Extreme INT
Raditz doesn't really find a place on Extreme INT; he does have a few useful links, but his damage output is not enough to consider him for the team under normal circumstances. The main reason why you would want to run this unit on your team is his AoE Super Attack, capable of getting you through the lower stages of the World Tournament under [Transcendent Majin] Buu (Kid)'s Leader Skill, so, excluding this case, he should be at best a floater
Super ATK
Raditz's Super Attack causes mass damage to all enemies and lowers their DEF. It's definitely nice to finally have an in-game obtainable unit with an AoE attack, but his multiplier is incredibly low: mass damage translates for extreme damage in terms of single target, a 355% multiplier at SA 10. His 12 Ki multiplier is 140%, average but not bad.
Leader Skill
Raditz is the first and only leader for the Low-Class Warrior category so far; his Leader Skill does give 4 Ki instead of 3 and 80% ATK, which is nice for consistency and damage, but only 40% for HP and DEF is pretty underwhelming. If we look at this unit for what he is, an in-game obtainable category leader, Raditz is not bad at all, but he definitely falls behind compared to [Expectations of Growth] Gohan (Kid) and [Getting Butterflies] Bulma (Youth)
Passive Skill
Raditz's Passive was designed for the World Tournament: 50% ATK when facing one enemy and 6 Ki and an additional 30% to both ATK and DEF when facing two or more. The first problem you will face in the World Tournament is consistency; all of your units will now receive only half of what they would normally get from the Leader Skill, 3 Ki instead of 6 usually, meaning it will be more difficult to Super Attack if your team is not cohesive enough. Why is Raditz so great? His Passive will always be completely active in the World Tournament environment, always giving him that 6 Ki and additional boost, making a lot easier to Super Attack.
Great linking partners, these two units share "Brutal Beatdown", "Nightmare" and "Saiyan Warrior Race", activating every ATK link Raditz has; in addition to this, Raditz's self-sufficiency makes it easier to save a bunch of Ki spheres for Raditz (Great Ape) to nuke with.
Turles is an amazing support unit and, while the Ki his Passive gives is not that useful for Raditz, the 20% ATK boost is definitely appreciated. Raditz and Turles share both "Prepared for Battle" and "Shattering the Limit", but not much in terms of ATK links.
Raditz and Vegeta link extremely well, activating every ATK links they have, with the exclusion of "Big Bad Bosses" for Vegeta; Raditz also receives 4 Ki and a 40% boost to both ATK and DEF from Vegeta's support Passive.
Hidden Potential
I would honestly not advise you to waste any orbs with this unit, he is a solid Free-To-Play character, but nothing more, especially considering how many great INT types were released recently and would appreciate those orbs more. Raditz receives only a +3000 stat boost from his Potential System and the main focus should be as always on Criticals and Additionals as he does already receive a natural lv.5 Dodge.
Should I use Elder Kais/Grand Kais?
Farming this unit is not that easy, but you can still use the Low-Class Warrior category to get a chance for a lucky drop, you should not use any Elder Kais or Grand Kais to max this unit out.